Episode Summary
At a farewell party before his departure to Germany, a drunk Gu Xuejiao kisses Lin Zhihua and confesses her secret about being a time traveler. The next morning, she only vaguely remembers the events. At their final goodbye, she is more concerned about whether she exposed her secret than his leaving. Disappointed, Lin Zhihua lies about what she said and departs, leaving her in a state of relieved uncertainty.
Spoiler Alert
With his departure for Germany finalized, Lin Zhihua's time is running out. When Gao Rui asks if Lin Zhiyue will come to see him off, Zhihua confirms she won't. He finds himself looking through Gu Xuejiao's calendar from the month before her college entrance exams, a glimpse into her past struggles. At the same time, in the lab, Xuejiao is cleaning equipment and nearly wipes away a label Zhihua made during his freshman year. This small act triggers a moment of realization for both of them. They instinctively rush to find each other, only to take different paths and miss one another completely.
Back in the lab, a classmate tells Xuejiao a boy is waiting for her downstairs. It turns out to be Yi Tianyu, there to turn in his tutoring homework. She has no choice but to review it with him on the spot. From a distance, Lin Zhihua sees them together and decides not to interrupt.
Meanwhile, Zhou Shiyun receives an official academic warning for her poor grades. Just then, an ecstatic Gu Mingze arrives, eager to share the news that his game has topped the charts for three consecutive weeks. His joy is cut short when she shows him the warning letter. Unfazed, Gu Mingze reassures her that he'll like her no matter what happens.
The lab holds a farewell party for Lin Zhihua's team. Feeling out of place and not knowing anyone well, Gu Xuejiao drinks by herself. Lin Zhihua eventually makes his way to her side. She uses the opportunity to ask him a metaphorical math question: how can a target function achieve rapid regression? He replies that practical testing is the best method, a clear allusion to their unspoken feelings. He adds that their mutual hesitation is only causing a stalemate. Seeing that she's already quite drunk, Zhihua decides to walk her back to her dorm.
They end up sitting by the campus sports field. Emboldened by the alcohol, Xuejiao leans in and kisses him. She drops the formal "senior" and calls him by his name, "Lin Zhihua," for the first time, giving him her old high school name tag as a keepsake. As he carries the intoxicated Xuejiao back to her dorm, she finally reveals her biggest secret: that she has traveled back in time from ten years in the future. The confession strikes a chord with Lin Zhihua, who recalls several instances where she seemed on the verge of saying something important, and he feels a strange sense of familiarity, as if he's had a similar experience himself.
The next morning, Xuejiao wakes up with a throbbing headache and a foggy memory of the night before. Her roommate, Sun Tiantian, has her try a new milk tea recipe, and the taste instantly unlocks her memories. She remembers kissing Lin Zhihua and has a dreadful feeling she also told him about her time-traveling secret, though she can't be entirely sure about the second part.
Lin Zhihua, having packed his things, is deliberately stalling by his taxi, sending Gao Rui on a pointless errand for souvenirs. Gao Rui is baffled by Zhihua's uncharacteristic inefficiency. Just as Zhihua hoped, Gu Xuejiao comes running to the lab to find him. A labmate, Lin Jiadong, tells her Zhihua has already left but forgot his portable hard drive. She grabs it and sprints outside.
Zhihua is waiting. He had hoped she would say something to convince him to stay. Instead, the first thing she asks is what she said while she was drunk. A wave of disappointment hits him. He lies, telling her she only asked a few questions about functions. Visibly relieved, Xuejiao simply watches as he gets into the car and drives away.
Back in her dorm, Xuejiao calculates that Zhihua has probably landed in Germany. She drafts and deletes a text message over and over, wanting to ask if she mentioned her secret but fearing that bringing it up would make her look guilty. Her anxiety spikes when her other roommate, Sun Feifei, mentions there's fresh gossip on campus. Xuejiao immediately assumes her secret is out. However, Feifei clarifies that the "gossip" is just about a new milk tea being sold at the cafeteria. Xuejiao breathes a sigh of relief, though the uncertainty about what she revealed remains.
